The rear impact guard of a trailer, semi-trailer, and/or flatbed trailer is generally provided to help prevent other vehicles in a rear-impact collision with such a trailer from traveling beyond the rear extremity of the trailer and into an area beneath the floor assembly of the trailer. Rear impact guards may also operate to absorb the energy of a rear impact from another vehicle. Rear impact guards typically include a horizontal member suspended from two struts attached to the bottom side of the trailer rear end wall.